The present invention relates in general to climate control systems in passenger vehicles, and, more specifically, to measuring interior temperature, humidity, or air quality for the purpose of controlling the operation of the climate control system.
Heating, ventilation, and air-conditioning (HVAC) systems with electronic automatic temperature control (EATC) need to obtain a measurement of an internal air temperature/humidity so that these can be controlled to a target value that is set by an occupant. Temperature and/or humidity in the passenger cabin have conventionally been measured using a small sensor or sensors located on the instrument panel ((i.e., dashboard) near the center of the vehicle. In order to provide an accurate characterization of a climate characteristic (temperature or humidity), it is desirable to ensure a significant flow of cabin air over the sensor. Conventional sensors are typically aspirated using 1) a suction line running from the HVAC air handling case to the sensor location on the instrument panel utilizing a venturi to pull air over the sensor, or 2) a small fan packaged with the sensor independent of the HVAC module. These approaches, however, can result in inadequate airflow and/or distracting noises resulting from the suction or from the motor.